Tracking the lineage or history of a data item such as a document can be accomplished in a number of ways using commercially available products. For example, Microsoft Word allows user to enter comments so that changes can be tracked as the document is edited. Products that keep track of document versions allow users to open and edit documents in a way that allows an administrator to keep track of each version after each edit. Content management systems also allow for the assignment of identifiers to recently created or modified work that resides in the system's repository.
These document tracking techniques offer the general ability to follow the life of a data item but each technique suffers from significant drawbacks, such as the absence of an ability to robustly track multiple formats of data items using a common scheme or a requirement for significant overhead and complex software to accomplish their task. For example, the comment and change tracking ability of Microsoft Word is specific to this software application, and does not apply to other data formats such as text documents, images, video, or even other Microsoft document formats. In addition, the information contained within the document is not preserved if the document is lost. Version trackers and content management systems typically require substantial overhead and significant storage space, because items to be tracked must be stored in a central repository where their use (checking in/out) is under strict control, and multiple versions of the items to be tracked must be stored.